Each time a "Six Samurai" monster(s) is Normal or Special Summoned, place 1 Bushido Counter on this card (max. 2). You can send this card to the Graveyard; draw 1 card for each Bushido Counter on this card.
Six Samurai United can very easily be fulfilled when put in a Six Samurai deck. Even being able to draw 2 cards the same turn it was activated. Here are some Six Samurai monsters that are particularly great at Swarming the field.
Shien’s Daredevil can remove a counter from himself and place it onto Six Samurai United. Unfortunately Shien’s Daredevil does not count as a Six Samurai monster so his summoning will not contribute to Six Samurai United.
I am using Stardust Charge Warrior as well because of 2 reasons:
1) it can draw one card when he is special summoned;
2) it can attack all the special summoned monsters that my oponent has.
So yeah... I think three is a bit too much because you want to end the match fast, not frustrate you re opponent.